The Tcpdump Group git mirrors - tcpdump/blob - print-cfm.c

   1 /*
   2  * Copyright (c) 1998-2006 The TCPDUMP project
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that: (1) source code
   6  * distributions retain the above copyright notice and this paragraph
   7  * in its entirety, and (2) distributions including binary code include
   8  * the above copyright notice and this paragraph in its entirety in
   9  * the documentation or other materials provided with the distribution.
  10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
  11  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  12  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  13  * FOR A PARTICULAR PURPOSE.
  14  *
  15  * Original code by Hannes Gredler (hannes@gredler.at)
  16  */
  17
  18 /* \summary: IEEE 802.1ag Connectivity Fault Management (CFM) protocols printer */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <netdissect-stdinc.h>
  25
  26 #include <stdio.h>
  27
  28 #include "netdissect.h"
  29 #include "extract.h"
  30 #include "ether.h"
  31 #include "addrtoname.h"
  32 #include "oui.h"
  33 #include "af.h"
  34
  35 struct cfm_common_header_t {
  36     uint8_t mdlevel_version;
  37     uint8_t opcode;
  38     uint8_t flags;
  39     uint8_t first_tlv_offset;
  40 };
  41
  42 #define CFM_VERSION 0
  43 #define CFM_EXTRACT_VERSION(x) (((x)&0x1f))
  44 #define CFM_EXTRACT_MD_LEVEL(x) (((x)&0xe0)>>5)
  45
  46 #define CFM_OPCODE_CCM 1
  47 #define CFM_OPCODE_LBR 2
  48 #define CFM_OPCODE_LBM 3
  49 #define CFM_OPCODE_LTR 4
  50 #define CFM_OPCODE_LTM 5
  51
  52 static const struct tok cfm_opcode_values[] = {
  53     { CFM_OPCODE_CCM, "Continuity Check Message"},
  54     { CFM_OPCODE_LBR, "Loopback Reply"},
  55     { CFM_OPCODE_LBM, "Loopback Message"},
  56     { CFM_OPCODE_LTR, "Linktrace Reply"},
  57     { CFM_OPCODE_LTM, "Linktrace Message"},
  58     { 0, NULL}
  59 };
  60
  61 /*
  62  * Message Formats.
  63  */
  64 struct cfm_ccm_t {
  65     uint8_t sequence[4];
  66     uint8_t ma_epi[2];
  67     uint8_t names[48];
  68     uint8_t itu_t_y_1731[16];
  69 };
  70
  71 /*
  72  * Timer Bases for the CCM Interval field.
  73  * Expressed in units of seconds.
  74  */
  75 static const float ccm_interval_base[8] = {0, 0.003333, 0.01, 0.1, 1, 10, 60, 600};
  76 #define CCM_INTERVAL_MIN_MULTIPLIER 3.25
  77 #define CCM_INTERVAL_MAX_MULTIPLIER 3.5
  78
  79 #define CFM_CCM_RDI_FLAG 0x80
  80 #define CFM_EXTRACT_CCM_INTERVAL(x) (((x)&0x07))
  81
  82 #define CFM_CCM_MD_FORMAT_8021 0
  83 #define CFM_CCM_MD_FORMAT_NONE 1
  84 #define CFM_CCM_MD_FORMAT_DNS  2
  85 #define CFM_CCM_MD_FORMAT_MAC  3
  86 #define CFM_CCM_MD_FORMAT_CHAR 4
  87
  88 static const struct tok cfm_md_nameformat_values[] = {
  89     { CFM_CCM_MD_FORMAT_8021, "IEEE 802.1"},
  90     { CFM_CCM_MD_FORMAT_NONE, "No MD Name present"},
  91     { CFM_CCM_MD_FORMAT_DNS, "DNS string"},
  92     { CFM_CCM_MD_FORMAT_MAC, "MAC + 16Bit Integer"},
  93     { CFM_CCM_MD_FORMAT_CHAR, "Character string"},
  94     { 0, NULL}
  95 };
  96
  97 #define CFM_CCM_MA_FORMAT_8021 0
  98 #define CFM_CCM_MA_FORMAT_VID  1
  99 #define CFM_CCM_MA_FORMAT_CHAR 2
 100 #define CFM_CCM_MA_FORMAT_INT  3
 101 #define CFM_CCM_MA_FORMAT_VPN  4
 102
 103 static const struct tok cfm_ma_nameformat_values[] = {
 104     { CFM_CCM_MA_FORMAT_8021, "IEEE 802.1"},
 105     { CFM_CCM_MA_FORMAT_VID, "Primary VID"},
 106     { CFM_CCM_MA_FORMAT_CHAR, "Character string"},
 107     { CFM_CCM_MA_FORMAT_INT, "16Bit Integer"},
 108     { CFM_CCM_MA_FORMAT_VPN, "RFC2685 VPN-ID"},
 109     { 0, NULL}
 110 };
 111
 112 struct cfm_lbm_t {
 113     uint8_t transaction_id[4];
 114 };
 115
 116 struct cfm_ltm_t {
 117     uint8_t transaction_id[4];
 118     uint8_t ttl;
 119     uint8_t original_mac[ETHER_ADDR_LEN];
 120     uint8_t target_mac[ETHER_ADDR_LEN];
 121 };
 122
 123 static const struct tok cfm_ltm_flag_values[] = {
 124     { 0x80, "Use Forwarding-DB only"},
 125     { 0, NULL}
 126 };
 127
 128 struct cfm_ltr_t {
 129     uint8_t transaction_id[4];
 130     uint8_t ttl;
 131     uint8_t replay_action;
 132 };
 133
 134 static const struct tok cfm_ltr_flag_values[] = {
 135     { 0x80, "UseFDB Only"},
 136     { 0x40, "FwdYes"},
 137     { 0x20, "Terminal MEP"},
 138     { 0, NULL}
 139 };
 140
 141 static const struct tok cfm_ltr_replay_action_values[] = {
 142     { 1, "Exact Match"},
 143     { 2, "Filtering DB"},
 144     { 3, "MIP CCM DB"},
 145     { 0, NULL}
 146 };
 147
 148
 149 #define CFM_TLV_END 0
 150 #define CFM_TLV_SENDER_ID 1
 151 #define CFM_TLV_PORT_STATUS 2
 152 #define CFM_TLV_INTERFACE_STATUS 3
 153 #define CFM_TLV_DATA 4
 154 #define CFM_TLV_REPLY_INGRESS 5
 155 #define CFM_TLV_REPLY_EGRESS 6
 156 #define CFM_TLV_PRIVATE 31
 157
 158 static const struct tok cfm_tlv_values[] = {
 159     { CFM_TLV_END, "End"},
 160     { CFM_TLV_SENDER_ID, "Sender ID"},
 161     { CFM_TLV_PORT_STATUS, "Port status"},
 162     { CFM_TLV_INTERFACE_STATUS, "Interface status"},
 163     { CFM_TLV_DATA, "Data"},
 164     { CFM_TLV_REPLY_INGRESS, "Reply Ingress"},
 165     { CFM_TLV_REPLY_EGRESS, "Reply Egress"},
 166     { CFM_TLV_PRIVATE, "Organization Specific"},
 167     { 0, NULL}
 168 };
 169
 170 /*
 171  * TLVs
 172  */
 173
 174 struct cfm_tlv_header_t {
 175     uint8_t type;
 176     uint8_t length[2];
 177 };
 178
 179 /* FIXME define TLV formats */
 180
 181 static const struct tok cfm_tlv_port_status_values[] = {
 182     { 1, "Blocked"},
 183     { 2, "Up"},
 184     { 0, NULL}
 185 };
 186
 187 static const struct tok cfm_tlv_interface_status_values[] = {
 188     { 1, "Up"},
 189     { 2, "Down"},
 190     { 3, "Testing"},
 191     { 5, "Dormant"},
 192     { 6, "not present"},
 193     { 7, "lower Layer down"},
 194     { 0, NULL}
 195 };
 196
 197 #define CFM_CHASSIS_ID_CHASSIS_COMPONENT 1
 198 #define CFM_CHASSIS_ID_INTERFACE_ALIAS 2
 199 #define CFM_CHASSIS_ID_PORT_COMPONENT 3
 200 #define CFM_CHASSIS_ID_MAC_ADDRESS 4
 201 #define CFM_CHASSIS_ID_NETWORK_ADDRESS 5
 202 #define CFM_CHASSIS_ID_INTERFACE_NAME 6
 203 #define CFM_CHASSIS_ID_LOCAL 7
 204
 205 static const struct tok cfm_tlv_senderid_chassisid_values[] = {
 206     { 0, "Reserved"},
 207     { CFM_CHASSIS_ID_CHASSIS_COMPONENT, "Chassis component"},
 208     { CFM_CHASSIS_ID_INTERFACE_ALIAS, "Interface alias"},
 209     { CFM_CHASSIS_ID_PORT_COMPONENT, "Port component"},
 210     { CFM_CHASSIS_ID_MAC_ADDRESS, "MAC address"},
 211     { CFM_CHASSIS_ID_NETWORK_ADDRESS, "Network address"},
 212     { CFM_CHASSIS_ID_INTERFACE_NAME, "Interface name"},
 213     { CFM_CHASSIS_ID_LOCAL, "Locally assigned"},
 214     { 0, NULL}
 215 };
 216
 217
 218 static int
 219 cfm_network_addr_print(netdissect_options *ndo,
 220                        register const u_char *tptr)
 221 {
 222     u_int network_addr_type;
 223     u_int hexdump =  FALSE;
 224
 225     /*
 226      * Altough AFIs are tpically 2 octects wide,
 227      * 802.1ab specifies that this field width
 228      * is only once octet
 229      */
 230     network_addr_type = *tptr;
 231     ND_PRINT((ndo, "\n\t  Network Address Type %s (%u)",
 232            tok2str(af_values, "Unknown", network_addr_type),
 233            network_addr_type));
 234
 235     /*
 236      * Resolve the passed in Address.
 237      */
 238     switch(network_addr_type) {
 239     case AFNUM_INET:
 240         ND_PRINT((ndo, ", %s", ipaddr_string(ndo, tptr + 1)));
 241         break;
 242
 243     case AFNUM_INET6:
 244         ND_PRINT((ndo, ", %s", ip6addr_string(ndo, tptr + 1)));
 245         break;
 246
 247     default:
 248         hexdump = TRUE;
 249         break;
 250     }
 251
 252     return hexdump;
 253 }
 254
 255 void
 256 cfm_print(netdissect_options *ndo,
 257           register const u_char *pptr, register u_int length)
 258 {
 259     const struct cfm_common_header_t *cfm_common_header;
 260     const struct cfm_tlv_header_t *cfm_tlv_header;
 261     const uint8_t *tptr, *tlv_ptr;
 262     const uint8_t *namesp;
 263     u_int names_data_remaining;
 264     uint8_t md_nameformat, md_namelength;
 265     const uint8_t *md_name;
 266     uint8_t ma_nameformat, ma_namelength;
 267     const uint8_t *ma_name;
 268     u_int hexdump, tlen, cfm_tlv_len, cfm_tlv_type, ccm_interval;
 269
 270
 271     union {
 272         const struct cfm_ccm_t *cfm_ccm;
 273         const struct cfm_lbm_t *cfm_lbm;
 274         const struct cfm_ltm_t *cfm_ltm;
 275         const struct cfm_ltr_t *cfm_ltr;
 276     } msg_ptr;
 277
 278     tptr=pptr;
 279     cfm_common_header = (const struct cfm_common_header_t *)pptr;
 280     if (length < sizeof(*cfm_common_header))
 281         goto tooshort;
 282     ND_TCHECK(*cfm_common_header);
 283
 284     /*
 285      * Sanity checking of the header.
 286      */
 287     if (CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version) != CFM_VERSION) {
 288         ND_PRINT((ndo, "CFMv%u not supported, length %u",
 289                CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version), length));
 290         return;
 291     }
 292
 293     ND_PRINT((ndo, "CFMv%u %s, MD Level %u, length %u",
 294            CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version),
 295            tok2str(cfm_opcode_values, "unknown (%u)", cfm_common_header->opcode),
 296            CFM_EXTRACT_MD_LEVEL(cfm_common_header->mdlevel_version),
 297            length));
 298
 299     /*
 300      * In non-verbose mode just print the opcode and md-level.
 301      */
 302     if (ndo->ndo_vflag < 1) {
 303         return;
 304     }
 305
 306     ND_PRINT((ndo, "\n\tFirst TLV offset %u", cfm_common_header->first_tlv_offset));
 307
 308     tptr += sizeof(const struct cfm_common_header_t);
 309     tlen = length - sizeof(struct cfm_common_header_t);
 310
 311     /*
 312      * Sanity check the first TLV offset.
 313      */
 314     if (cfm_common_header->first_tlv_offset > tlen) {
 315         ND_PRINT((ndo, " (too large, must be <= %u)", tlen));
 316         return;
 317     }
 318
 319     switch (cfm_common_header->opcode) {
 320     case CFM_OPCODE_CCM:
 321         msg_ptr.cfm_ccm = (const struct cfm_ccm_t *)tptr;
 322         if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ccm)) {
 323             ND_PRINT((ndo, " (too small 1, must be >= %lu)",
 324                      (unsigned long) sizeof(*msg_ptr.cfm_ccm)));
 325             return;
 326         }
 327         if (tlen < sizeof(*msg_ptr.cfm_ccm))
 328             goto tooshort;
 329         ND_TCHECK(*msg_ptr.cfm_ccm);
 330
 331         ccm_interval = CFM_EXTRACT_CCM_INTERVAL(cfm_common_header->flags);
 332         ND_PRINT((ndo, ", Flags [CCM Interval %u%s]",
 333                ccm_interval,
 334                cfm_common_header->flags & CFM_CCM_RDI_FLAG ?
 335                ", RDI" : ""));
 336
 337         /*
 338          * Resolve the CCM interval field.
 339          */
 340         if (ccm_interval) {
 341             ND_PRINT((ndo, "\n\t  CCM Interval %.3fs"
 342                    ", min CCM Lifetime %.3fs, max CCM Lifetime %.3fs",
 343                    ccm_interval_base[ccm_interval],
 344                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MIN_MULTIPLIER,
 345                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MAX_MULTIPLIER));
 346         }
 347
 348         ND_PRINT((ndo, "\n\t  Sequence Number 0x%08x, MA-End-Point-ID 0x%04x",
 349                EXTRACT_32BITS(msg_ptr.cfm_ccm->sequence),
 350                EXTRACT_16BITS(msg_ptr.cfm_ccm->ma_epi)));
 351
 352         namesp = msg_ptr.cfm_ccm->names;
 353         names_data_remaining = sizeof(msg_ptr.cfm_ccm->names);
 354
 355         /*
 356          * Resolve the MD fields.
 357          */
 358         md_nameformat = *namesp;
 359         namesp++;
 360         names_data_remaining--;  /* We know this is != 0 */
 361         if (md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
 362             md_namelength = *namesp;
 363             namesp++;
 364             names_data_remaining--; /* We know this is !=0 */
 365             ND_PRINT((ndo, "\n\t  MD Name Format %s (%u), MD Name length %u",
 366                    tok2str(cfm_md_nameformat_values, "Unknown",
 367                            md_nameformat),
 368                    md_nameformat,
 369                    md_namelength));
 370
 371             /*
 372              * -3 for the MA short name format and length and one byte
 373              * of MA short name.
 374              */
 375             if (md_namelength > names_data_remaining - 3) {
 376                 ND_PRINT((ndo, " (too large, must be <= %u)", names_data_remaining - 2));
 377                 return;
 378             }
 379
 380             md_name = namesp;
 381             ND_PRINT((ndo, "\n\t  MD Name: "));
 382             switch (md_nameformat) {
 383             case CFM_CCM_MD_FORMAT_DNS:
 384             case CFM_CCM_MD_FORMAT_CHAR:
 385                 safeputs(ndo, md_name, md_namelength);
 386                 break;
 387
 388             case CFM_CCM_MD_FORMAT_MAC:
 389                 if (md_namelength == 6) {
 390                     ND_PRINT((ndo, "\n\t  MAC %s", etheraddr_string(ndo,
 391                                md_name)));
 392                 } else {
 393                     ND_PRINT((ndo, "\n\t  MAC (length invalid)"));
 394                 }
 395                 break;
 396
 397                 /* FIXME add printers for those MD formats - hexdump for now */
 398             case CFM_CCM_MA_FORMAT_8021:
 399             default:
 400                 print_unknown_data(ndo, md_name, "\n\t    ",
 401                                    md_namelength);
 402             }
 403             namesp += md_namelength;
 404             names_data_remaining -= md_namelength;
 405         } else {
 406             ND_PRINT((ndo, "\n\t  MD Name Format %s (%u)",
 407                    tok2str(cfm_md_nameformat_values, "Unknown",
 408                            md_nameformat),
 409                    md_nameformat));
 410         }
 411
 412
 413         /*
 414          * Resolve the MA fields.
 415          */
 416         ma_nameformat = *namesp;
 417         namesp++;
 418         names_data_remaining--; /* We know this is != 0 */
 419         ma_namelength = *namesp;
 420         namesp++;
 421         names_data_remaining--; /* We know this is != 0 */
 422         ND_PRINT((ndo, "\n\t  MA Name-Format %s (%u), MA name length %u",
 423                tok2str(cfm_ma_nameformat_values, "Unknown",
 424                        ma_nameformat),
 425                ma_nameformat,
 426                ma_namelength));
 427
 428         if (ma_namelength > names_data_remaining) {
 429             ND_PRINT((ndo, " (too large, must be <= %u)", names_data_remaining));
 430             return;
 431         }
 432
 433         ma_name = namesp;
 434         ND_PRINT((ndo, "\n\t  MA Name: "));
 435         switch (ma_nameformat) {
 436         case CFM_CCM_MA_FORMAT_CHAR:
 437             safeputs(ndo, ma_name, ma_namelength);
 438             break;
 439
 440             /* FIXME add printers for those MA formats - hexdump for now */
 441         case CFM_CCM_MA_FORMAT_8021:
 442         case CFM_CCM_MA_FORMAT_VID:
 443         case CFM_CCM_MA_FORMAT_INT:
 444         case CFM_CCM_MA_FORMAT_VPN:
 445         default:
 446             print_unknown_data(ndo, ma_name, "\n\t    ", ma_namelength);
 447         }
 448         break;
 449
 450     case CFM_OPCODE_LTM:
 451         msg_ptr.cfm_ltm = (const struct cfm_ltm_t *)tptr;
 452         if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ltm)) {
 453             ND_PRINT((ndo, " (too small 4, must be >= %lu)",
 454                      (unsigned long) sizeof(*msg_ptr.cfm_ltm)));
 455             return;
 456         }
 457         if (tlen < sizeof(*msg_ptr.cfm_ltm))
 458             goto tooshort;
 459         ND_TCHECK(*msg_ptr.cfm_ltm);
 460
 461         ND_PRINT((ndo, ", Flags [%s]",
 462                bittok2str(cfm_ltm_flag_values, "none", cfm_common_header->flags)));
 463
 464         ND_PRINT((ndo, "\n\t  Transaction-ID 0x%08x, ttl %u",
 465                EXTRACT_32BITS(msg_ptr.cfm_ltm->transaction_id),
 466                msg_ptr.cfm_ltm->ttl));
 467
 468         ND_PRINT((ndo, "\n\t  Original-MAC %s, Target-MAC %s",
 469                etheraddr_string(ndo, msg_ptr.cfm_ltm->original_mac),
 470                etheraddr_string(ndo, msg_ptr.cfm_ltm->target_mac)));
 471         break;
 472
 473     case CFM_OPCODE_LTR:
 474         msg_ptr.cfm_ltr = (const struct cfm_ltr_t *)tptr;
 475         if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ltr)) {
 476             ND_PRINT((ndo, " (too small 5, must be >= %lu)",
 477                      (unsigned long) sizeof(*msg_ptr.cfm_ltr)));
 478             return;
 479         }
 480         if (tlen < sizeof(*msg_ptr.cfm_ltr))
 481             goto tooshort;
 482         ND_TCHECK(*msg_ptr.cfm_ltr);
 483
 484         ND_PRINT((ndo, ", Flags [%s]",
 485                bittok2str(cfm_ltr_flag_values, "none", cfm_common_header->flags)));
 486
 487         ND_PRINT((ndo, "\n\t  Transaction-ID 0x%08x, ttl %u",
 488                EXTRACT_32BITS(msg_ptr.cfm_ltr->transaction_id),
 489                msg_ptr.cfm_ltr->ttl));
 490
 491         ND_PRINT((ndo, "\n\t  Replay-Action %s (%u)",
 492                tok2str(cfm_ltr_replay_action_values,
 493                        "Unknown",
 494                        msg_ptr.cfm_ltr->replay_action),
 495                msg_ptr.cfm_ltr->replay_action));
 496         break;
 497
 498         /*
 499          * No message decoder yet.
 500          * Hexdump everything up until the start of the TLVs
 501          */
 502     case CFM_OPCODE_LBR:
 503     case CFM_OPCODE_LBM:
 504     default:
 505         print_unknown_data(ndo, tptr, "\n\t  ",
 506                            tlen -  cfm_common_header->first_tlv_offset);
 507         break;
 508     }
 509
 510     tptr += cfm_common_header->first_tlv_offset;
 511     tlen -= cfm_common_header->first_tlv_offset;
 512
 513     while (tlen > 0) {
 514         cfm_tlv_header = (const struct cfm_tlv_header_t *)tptr;
 515
 516         /* Enough to read the tlv type ? */
 517         ND_TCHECK2(*tptr, 1);
 518         cfm_tlv_type=cfm_tlv_header->type;
 519
 520         ND_PRINT((ndo, "\n\t%s TLV (0x%02x)",
 521                tok2str(cfm_tlv_values, "Unknown", cfm_tlv_type),
 522                cfm_tlv_type));
 523
 524         if (cfm_tlv_type == CFM_TLV_END) {
 525             /* Length is "Not present if the Type field is 0." */
 526             return;
 527         }
 528
 529         /* do we have the full tlv header ? */
 530         if (tlen < sizeof(struct cfm_tlv_header_t))
 531             goto tooshort;
 532         ND_TCHECK2(*tptr, sizeof(struct cfm_tlv_header_t));
 533         cfm_tlv_len=EXTRACT_16BITS(&cfm_tlv_header->length);
 534
 535         ND_PRINT((ndo, ", length %u", cfm_tlv_len));
 536
 537         tptr += sizeof(struct cfm_tlv_header_t);
 538         tlen -= sizeof(struct cfm_tlv_header_t);
 539         tlv_ptr = tptr;
 540
 541         /* do we have the full tlv ? */
 542         if (tlen < cfm_tlv_len)
 543             goto tooshort;
 544         ND_TCHECK2(*tptr, cfm_tlv_len);
 545         hexdump = FALSE;
 546
 547         switch(cfm_tlv_type) {
 548         case CFM_TLV_PORT_STATUS:
 549             if (cfm_tlv_len < 1) {
 550                 ND_PRINT((ndo, " (too short, must be >= 1)"));
 551                 return;
 552             }
 553             ND_PRINT((ndo, ", Status: %s (%u)",
 554                    tok2str(cfm_tlv_port_status_values, "Unknown", *tptr),
 555                    *tptr));
 556             break;
 557
 558         case CFM_TLV_INTERFACE_STATUS:
 559             if (cfm_tlv_len < 1) {
 560                 ND_PRINT((ndo, " (too short, must be >= 1)"));
 561                 return;
 562             }
 563             ND_PRINT((ndo, ", Status: %s (%u)",
 564                    tok2str(cfm_tlv_interface_status_values, "Unknown", *tptr),
 565                    *tptr));
 566             break;
 567
 568         case CFM_TLV_PRIVATE:
 569             if (cfm_tlv_len < 4) {
 570                 ND_PRINT((ndo, " (too short, must be >= 4)"));
 571                 return;
 572             }
 573             ND_PRINT((ndo, ", Vendor: %s (%u), Sub-Type %u",
 574                    tok2str(oui_values,"Unknown", EXTRACT_24BITS(tptr)),
 575                    EXTRACT_24BITS(tptr),
 576                    *(tptr + 3)));
 577             hexdump = TRUE;
 578             break;
 579
 580         case CFM_TLV_SENDER_ID:
 581         {
 582             u_int chassis_id_type, chassis_id_length;
 583             u_int mgmt_addr_length;
 584
 585             if (cfm_tlv_len < 1) {
 586                 ND_PRINT((ndo, " (too short, must be >= 1)"));
 587                 return;
 588             }
 589
 590             /*
 591              * Get the Chassis ID length and check it.
 592              */
 593             chassis_id_length = *tptr;
 594             tptr++;
 595             tlen--;
 596             cfm_tlv_len--;
 597
 598             if (chassis_id_length) {
 599                 if (cfm_tlv_len < 1) {
 600                     ND_PRINT((ndo, "\n\t  (TLV too short)"));
 601                     return;
 602                 }
 603                 chassis_id_type = *tptr;
 604                 cfm_tlv_len--;
 605                 ND_PRINT((ndo, "\n\t  Chassis-ID Type %s (%u), Chassis-ID length %u",
 606                        tok2str(cfm_tlv_senderid_chassisid_values,
 607                                "Unknown",
 608                                chassis_id_type),
 609                        chassis_id_type,
 610                        chassis_id_length));
 611
 612                 if (cfm_tlv_len < chassis_id_length) {
 613                     ND_PRINT((ndo, "\n\t  (TLV too short)"));
 614                     return;
 615                 }
 616
 617                 switch (chassis_id_type) {
 618                 case CFM_CHASSIS_ID_MAC_ADDRESS:
 619                     ND_PRINT((ndo, "\n\t  MAC %s", etheraddr_string(ndo, tptr + 1)));
 620                     break;
 621
 622                 case CFM_CHASSIS_ID_NETWORK_ADDRESS:
 623                     hexdump |= cfm_network_addr_print(ndo, tptr);
 624                     break;
 625
 626                 case CFM_CHASSIS_ID_INTERFACE_NAME: /* fall through */
 627                 case CFM_CHASSIS_ID_INTERFACE_ALIAS:
 628                 case CFM_CHASSIS_ID_LOCAL:
 629                 case CFM_CHASSIS_ID_CHASSIS_COMPONENT:
 630                 case CFM_CHASSIS_ID_PORT_COMPONENT:
 631                     safeputs(ndo, tptr + 1, chassis_id_length);
 632                     break;
 633
 634                 default:
 635                     hexdump = TRUE;
 636                     break;
 637                 }
 638                 cfm_tlv_len -= chassis_id_length;
 639
 640                 tptr += 1 + chassis_id_length;
 641                 tlen -= 1 + chassis_id_length;
 642             }
 643
 644             /*
 645              * Check if there is a Management Address.
 646              */
 647             if (cfm_tlv_len == 0) {
 648                 /* No, there isn't; we're done. */
 649                 return;
 650             }
 651
 652             mgmt_addr_length = *tptr;
 653             tptr++;
 654             tlen--;
 655             cfm_tlv_len--;
 656             if (mgmt_addr_length) {
 657                 if (cfm_tlv_len < mgmt_addr_length) {
 658                     ND_PRINT((ndo, "\n\t  (TLV too short)"));
 659                     return;
 660                 }
 661                 cfm_tlv_len -= mgmt_addr_length;
 662                 /*
 663                  * XXX - this is an OID; print it as such.
 664                  */
 665                 tptr += mgmt_addr_length;
 666                 tlen -= mgmt_addr_length;
 667
 668                 if (cfm_tlv_len < 1) {
 669                     ND_PRINT((ndo, "\n\t  (TLV too short)"));
 670                     return;
 671                 }
 672
 673                 mgmt_addr_length = *tptr;
 674                 tptr++;
 675                 tlen--;
 676                 cfm_tlv_len--;
 677                 if (mgmt_addr_length) {
 678                     if (cfm_tlv_len < mgmt_addr_length) {
 679                         ND_PRINT((ndo, "\n\t  (TLV too short)"));
 680                         return;
 681                     }
 682                     cfm_tlv_len -= mgmt_addr_length;
 683                     /*
 684                      * XXX - this is a TransportDomain; print it as such.
 685                      */
 686                     tptr += mgmt_addr_length;
 687                     tlen -= mgmt_addr_length;
 688                 }
 689             }
 690             break;
 691         }
 692
 693             /*
 694              * FIXME those are the defined TLVs that lack a decoder
 695              * you are welcome to contribute code ;-)
 696              */
 697
 698         case CFM_TLV_DATA:
 699         case CFM_TLV_REPLY_INGRESS:
 700         case CFM_TLV_REPLY_EGRESS:
 701         default:
 702             hexdump = TRUE;
 703             break;
 704         }
 705         /* do we want to see an additional hexdump ? */
 706         if (hexdump || ndo->ndo_vflag > 1)
 707             print_unknown_data(ndo, tlv_ptr, "\n\t  ", cfm_tlv_len);
 708
 709         tptr+=cfm_tlv_len;
 710         tlen-=cfm_tlv_len;
 711     }
 712     return;
 713
 714 tooshort:
 715     ND_PRINT((ndo, "\n\t\t packet is too short"));
 716     return;
 717
 718 trunc:
 719     ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
 720 }